CodeAlmanac is an open-source, local, and free wiki designed for AI coding agents, capturing undocumented knowledge like decisions, flows, and gotchas. It addresses the issue of valuable information within AI conversations being lost.

CodeAlmanac automatically maintains a "almanac/" folder within a repository, creating connected Markdown pages. These pages document aspects not typically found in code, such as the reasoning behind architectural choices. The wiki is indexed in SQLite and accessible via a CLI, with instructions for agents to search it before coding.

Every five hours, CodeAlmanac uses the Codex/CC SDK to update relevant pages based on recent conversations. Initially built for individual developers, it has proven valuable for teams by preserving decision-making context. The tool is available for macOS with Codex or Claude Code and requires Python 3.12+.